Question Author
you can see them gleaming from space, shaney.
Our neighbourhood is built on farmland, about 1910. However, there's a detailed OS map from 1890 or thereabouts, and when you line it up with Google maps we're right on the farm pond. The ground was dry as a bone for our first 10 years or so, then, I don't know, a source reopened or the neighbours concreted their back yard or it rained more or something, but all of a sudden the ground got a lot wetter. I suppose it's since then the house has been really moving around and cracking.